Problem with objects colliding and IsSleeping (C#)

So I have a problem with one of my exploding enemies. The enemy first moves to a position that is set through an array, when it reaches the position the enemy will stay still and I use an if statement and ask "if the enemy == is sleeping". If it is a timer will start to countdown, when it reaches 0 the enemy explodes!

Now the problem is that there are other enemies that collide with the enemy when it is stationary, this makes the timer stutter since enemy is not "sleeping", since moves a little bit every time an object touches it!

What is the best way to solve this problem? I still want collision on the enemy even when it is stationary, but how could I make it so that the enemy is still stationary even though an object collides with it?

Here's the code:

 using UnityEngine;
 using System.Collections;
 
 public class EnemyExplodeScript : MonoBehaviour {
     
     //private Transform target;
     public Transform[] moveToPoints;
 
     //public GameObject explodingEnemy;
 
     public Transform explodingEnemyTransform;
 
 
     int movePoint = 0; 
     public float speed;
     public float explodeTimer = 3.0f;
 
     public Rigidbody2D enemyMove;
 
     
 
     void Start () 
     {
         //Find the which points the enemy should follow in the array
         moveToPoints[0] = GameObject.Find("MoveRightUp").transform;
         moveToPoints[1] = GameObject.Find("MoveLeftDown").transform;
         moveToPoints[2] = GameObject.Find("MoveRightDown").transform;
         moveToPoints[3] = GameObject.Find("MoveRightUp").transform;
         moveToPoints[4] = GameObject.Find("MoveMiddle").transform;
 
         //Set where the enemy should go with the array
         movePoint = Random.Range(0, moveToPoints.Length);
 
     }
 
 
     void Update () 
     {
         // Speed and time 
         float step = speed * Time.deltaTime;
 
         //Get the enemy moving
         transform.Translate (Vector3.MoveTowards (transform.position, moveToPoints[movePoint].position, step) - transform.position);
 
         //**Check if the enemy is stationary**
         if(enemyMove.IsSleeping())
         {
             //Start timer 
             explodeTimer -= Time.deltaTime;
         }
 
         //After 3 seconds destroy object
         if(explodeTimer <= 0.0f)
         {
             //ExplosionSpawnEnemy();
             Destroy(gameObject);
         }
 
 
 
     }